Case presentation
Initial evaluation
A 76-year-old man visited his family physician at the end of April X (year) due to visual disturbance in the left eye and was referred to our department on May 27, X. Ophthalmological history included bilateral cataract surgery, left ptosis (both in X-4 years), intrascleral fixation of left intraocular lens dislocation (in X-1 year), Irvine Gass syndrome, and ocular hypertension. Detailed history-taking revealed that the patient received treatment for IgG4-related disease (retroperitoneal fibrosis; prednisolone 2.5 mg/day) from his primary care physician.
Current medical history
At the initial visit on June 2 X, there was no conjunctival hyperemia in both conjunctivae, and anterior chamber cells were mildly present on the left eye. The left optic nerve papilla was mildly erythematous and swollen. Visual acuities were 1.2 (1.2 × S +1.75D) in the right eye and 0.6 (0.7 × S +2.00D) in the left eye, and intraocular pressures were 18 mmHg in the right eye and 16 mmHg in the left eye. Critical flicker frequency (CFF) was decreased in the left eye (right ↑38Hz↓41Hz, left ↑36Hz↓36Hz), and Humphrey visual field test revealed inferior auriculotemporal one-quarter blindness in the left eye (Figure 1). Brain magnetic resonance imaging (MRI) showed no abnormal signal in the infraorbital optic nerve; however, marked pituitary/pituitary sclerenchyma enlargement with associated optic chiasm compression was observed (Figure 2).
Intervention description/results
Based on the history and initial evaluation findings, a diagnosis of left optic neuropathy associated with pituitary/pituitary scrofula enlargement caused by IgG4-related disease was made. On June 10, visual acuity and visual field defects improved (Figure 3), and upon examination on July 7, the pituitary gland and pituitary pattern were almost normalized (Figure 4), and the CFF decreased (right ↑42Hz↓43Hz, left ↑37Hz↓43Hz) (39 Hz). The steroid dose was gradually decreased, and maintenance therapy with 2.5-mg prednisolone daily was resumed on August 11.